#define FUSE_USE_VERSION  26
   
#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

static const char *hello_str = "Hello World!\n";
static const char *hello_path = "/hello";

static int hello_getattr(const char *path, struct stat *stbuf)
{
  int res = 0;
  memset(stbuf, 0, sizeof(struct stat));
  if(strcmp(path, "/") == 0) {
      stbuf->st_mode = S_IFDIR | 0755;
      stbuf->st_nlink = 2;
  }
  else if(strcmp(path, hello_path) == 0) {
      stbuf->st_mode = S_IFREG | 0444;
      stbuf->st_nlink = 1;
      stbuf->st_size = strlen(hello_str);
  }
  else
      res = -ENOENT;

  return res;
}

static int hello_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                       off_t offset, struct fuse_file_info *fi)
{
  (void) offset;
  (void) fi;

  if(strcmp(path, "/") != 0)
      return -ENOENT;

  filler(buf, ".", NULL, 0);
  filler(buf, "..", NULL, 0);
  filler(buf, hello_path + 1, NULL, 0);

  return 0;
}

static int hello_open(const char *path, struct fuse_file_info *fi)
{
  if(strcmp(path, hello_path) != 0)
      return -ENOENT;

  if((fi->flags & 3) != O_RDONLY)
      return -EACCES;

  return 0;
}

static int hello_read(const char *path, char *buf, size_t size, off_t offset,
                    struct fuse_file_info *fi)
{
  size_t len;
  (void) fi;
  if(strcmp(path, hello_path) != 0)
      return -ENOENT;

  len = strlen(hello_str);
  if (offset < len) {
      if (offset + size > len)
          size = len - offset;
      memcpy(buf, hello_str + offset, size);
  } else
      size = 0;

  return size;
}

static struct fuse_operations hello_oper = {
  .getattr   = hello_getattr,
  .readdir = hello_readdir,
  .open   = hello_open,
  .read   = hello_read,
};

int main(int argc, char *argv[])
{
  return fuse_main(argc, argv, &hello_oper, NULL);
}

